Television system



Aug. 30, 1932. Q DAVIS 1,874,172

TELEVISION SYSTEM Filed July 5, 1950 2 Sheets-Sheet l INVEN TOR.

go Cw Q0 @MM Aug. 30, 1932. c. DAVIS TELEVISION SYSTEM Filed July 3, 1930 2 Sheets-Sheet 2 m n Hm moz amo 7. so

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Qfwfm S3, gm/v10 A T TURN E n H mm m, M NJ NM. W M \m l H Patented Aug. 39,1932

- we r 'r 'onns'rnn L. Davis, on K-EOKUK, IOWA, .ASSIGNOB TO WIRED nAmo, 1no., or i-inwf YonK, n. Y., A CORPORATION on DELAWARE v TELEVISION SYSTEM Application filed July' 3, 1930. Serial No. 465303;

system having means for modulating a luminously responsive screen at a receiver accordmg to incoming television signaling energy in for the reproduction of an image.

- Another'object of my 1I1V611l110111S'i30 pro{ vide a television receiving circuit including a luminously responsive screen adapted to reproduce television signalling energy according to the movement or" a potential node along. the screen wherein circuits are provided for normally activating the image reproducing screen and modifying the luminous discharge A thereof according to variations in the incommg" television signaling energy.-

My invention is directed to that class of televisionsystems shown more fully in my Letters Patent No.1,756,086, dated April 29, v 1930, entitled Signaling system, and: shown in my application Serial No. 299, 501, filed August 14, 1928,,en-titled @vlow discharge'de-- vice, .now Patent No. 1,789,219, dated Jan. 13,1930,application Serial No. 414,957,. filed December 18,. 1929 .entitled Television sysgo tem, and applicatiton Serial No; 43%,777, filed March 10, 1930-, entitled Transmission system; Fora further understanding of the television system of my invention reference is'made tomy cop'ending application Serial No- 60 ,760, filed June12, 1930, entitled Television system. v I

present invention will be more fully understood-from the specification following by reference to the accompanying drawings,- inwhich; A c

Figure 1 is a diagrammatic circuit arrangement of television system embodying the.

principles of my invention; Fig. 2 is a mod-i: fled circuit arrangement of a television sys- V tern embodying the principlesfotmy invention; and 31s. a diagrammatic illustra tlOHOfQgtQlGV-ISIOH transmitter.

Referring particularly toFig. 1, areceiv lnzg circuit has been illustrated as comprising antenna 1; connected to ground through the primary winding 2 of a coupling transformer which has a'secondary winding 3 connected to the first stage of radio frequency ampli-i fication indicated at 4c. A second stagebf radio frequency amplification is indicated at 5. The input circuits of each of theradio frequency amplifier stages are-aperiodically tuned by virtue of the-characteristics of the coupling transformers 30 and 31 in connection with the shunt condensers 32 and'33. The output coupling transformer 6 connects to a synchroscopecircuit designated. generallyat' 7. The synchroscope circuit comprises fixed windings 1'3 and '14 connected in series and energized by constant frequency oscils lator 15 controlled by pi'ezo electric crystal element 35; The movable windings 8 and 9 of the synchroscope 7 are connected in separate dephasing circuits containing impedances 10 and 11 in series with winding 9 and inductance 12 in series with winding 8. The mov-' able windings 8 and 9' are arranged-in predetermined angular positions and are connected through link 16 with variable condenser 17 which is disposed in circuit with an oscillator 18. The oscillator 18 includes input circuit 19' and output circuit 20. The image reproducing screen which is described more fully in my copending application Se ria'l No. 299,501, filed August 145, 1928, is corinectedin circuit with the oscillator 18 in such manner that the glow discharge Which'takes place within the enclosing envelope 36 is nor mall'y at uniform intensity throughout the length of the turns of the inductance 21. The condenser 17 which is connected in circuit with the-inductance 21 and in-circu'it with the'oscillator18' as shown when: in normal position does not vary the intensity or position of illumination. on the screen'- 21. However, when condenser 17 is varied due tomove ment of the synchroscope windings Sand 9 in proportion to the change in frequencyover the frequency band. which is passed by the substantially aperiodic circuits 30%32- and 31-33 will control the position of thenode:

i The luminous discharge of screen 21 is modulated by impressing received signaling energy from conductors 22 across a part of theoscfllator circuit as indicated at condenser-'23;-

rss PATENT O I B The modulation of oscillator 18 by the received signaling energy. may be accomplished in any manner well known to those skilled in the art. The potential drop along impedance 10 is transferred along conductors 22 across the condenser 23 thus controlling theintensity of the. glow. discharge at a potential node which moves along screen 21 acccording tov the capacity variation of condenser 17 for the reproduction of an image.

In the circuit illustrated in F ig. 2, I have shown means for eliminating a constant frequency oscillator at the receiver and employ ing in lieu thereof the standard source of sixty cycle alternating current lighting energy which is connected to leads 29 and passes through series connected windings 13 and 14 of the synchroscope. The energy which is passed through windings 8 and 9 of the synchroscope 7 in this modification is of an audio frequency inasmuch as I provide a detector 25 connected to the frequency band responsive circuits -32 and31-33. An audio frequency amplifier consisting of power amplification stages 26 and 27 connect to the output of detector 25. .The output of audio frequency transformer 28 connects'to the circuits of the synchroscope. In this arrangement the television transmitter, shown diagrammatically in Fig. 3, is modulated plus and minus sixty cycles, and as the modulation Varies at the receiving station, condenser 17 in Fig. 2 which is connected in the oscillator circuit 18, is automatically shifted through mechanical linkage 16 and the'potential along conductors 22 is varied for correspondingly controlling the movement and intensity of a potential node along the luminous discharge screen 21. The transmitter circuit in Fig. 2 is similarto the television circuit set forth in my Letters Patent 1,756,086 except that the oscillator is subjected to constant modulation by the cycle oscillator or lighting line circuit indicated at 37. The television scanning disc isrepresented at '38 operating to activate photo cell 39 according to the object &0 for correspondingly controlling the modulation of the transmitter under the influence of the photo cell 39.

The television signaling energy is emitted over a predetermined recurring frequency band by the coordination of the timing means 41 in the transmitting circuit with the operationof the scanning disc 38.

It will be seen that the incoming signaL' ingenergy in both circuit arrangements of my invention serves to control the effects of the oscillator 18 upon the luminous discharge tube 21. Due to rapidity in movement of potential nodes along the luminous discharge screen, the visual effects are integrated and the persistence of vision of the eye of an observer results in the visual reproduction of the image ofthe object which is scanned at the distant transmitter.

the position of condenser 17 through the movement of link 16. Accordingly, the position of a potential node along screen 21 is directly controlled by movement of condenser 17 which changes the frequency of the energy from oscillator 18 which is applied to the inductive screen 21. At the same time the variation in intensity of the received signaling energy through circuit 22 modulates oscillator 18 thereby decreasing or increasing the brilliancy of the various potential nodes set up along the inductance 21 for the reproduction of an image.

While vI have described my invention in certain preferred embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

l/Vhat I claim as new and desire to secure by Letters Patent of the United States is as follows: i

1. In a television system, means for receiving television signaling energy over a variable frequency range, an inductance constituting a glow discharge screen, means in circuit with said screen for normally energizing said glow discharge screen for producing a predetermined optical efi'ect thereon, and means operated by the incoming signaling energy for changing the frequency response characteristics of said glow discharge screen and simultaneously modulating the energy in circuit with the glow discharge screen according to variations in the incoming signaling energy.

2. A television system comprising a receiving circuit responsive to variable frequency signaling energy, a glow discharge screen connected with said circuit for variably responding to changes in incoming signaling energy, said glow discharge screen and a variable impedance disposed in circuit with said screen, said impedance being controllable'according to changes in frequency of the incoming signaling energy for controlling the potential distribution along said screen thereof acc0rding-to the variations of incoming signaling energy.

3. In a television system, a signal receiving circuit responsive to variable frequency signaling energy, a glow discharge screen comprising an inductance, means for impressing means for independently energizing ame and separate means for energizing said glow discharge screen in proportion to frequency changes in the incoming signaling energy.

4. In a television system, a receiving circuit responsive to changes in incoming signaling energy over a predetermined frequency band, an inductance constituting a glow discharge screen, means for energizing said glow discharge screen for producing a predetermined opticalefiect thereon, connections for varying the energization of the inductance constituting said screen accord ing to variations in intensity of the incoming signaling energy, and separate means connected with said receiving circuit for controlling the position of maximum luminosity of said glow discharge screen according to changes in frequency of the incoming signaling energy.

5. In a television system, a receiving circuit responsive to a variable range of frequencies, a screen constituted by an inductance, means for impressing incoming television signaling energy on said screen, independent means for normally exciting the inductance constituting said screen for producing a predetermined optical efi'ect thereon and a variable impedance device connected in circuit with the inductance constituting'said screen and controlled by said receiving circuit for shifting the position of a potential node along said screen according to changes in frequency of the incoming signaling energy.

6. In a television receiving system, a receiving circuit responsive to a predetermined band of frequencies, an inductance forming an image reproducing screen, means for normally exciting said inductance for producing a predetermined optical effect thereon, and means connected in series with said screen and controlled by the received television signaling energy for varying the excitation of the inductance constituting said screen according to changes in frequency of the incoming signaling energy. I

7. In a television receiving system, a receiving circuit responsive to a variable range of frequencies, an inductance comprising an image reproducing screen connected with said receiving circuit, an oscillator for normally exciting said inductance independently of said receiving circuit for producing a predetermined optical effect upon said screen, an angularly shiftable device controlled by said receiving circuit and connected with said screen for variably controlling the excitation of said sceen according to changes in frequency of the incoming signaling energy.

8. A television receiving system compris ing a receiving circuit responsive to a prede-V termined band of frequencies, an image reproducing screen constltuted by an inductance, an oscillator connected wlth said inductance for ccmjingsignaling ene- 5 r l 1 9 television tem airece vingmir- .cu taresponsive to :rflrfPI'BdGtBL-Hllllfld; band of ffrequencies, I ran; "zl age" :reproducing; screen constituted by an inductance connected-with Tl said receiving cincnitaan".oscillator connected witrrsaid sinduetance for norn al exciting said-..inducta-nce:'and;producing a predetenmined? optical .e ffecti thereen means :for con;- trolling the-ramplitude'otexcitationaccording to; the amplitude-cf;the.Lreeeivedasignalingaenergy, aein'otor device driven bysthe incoming sign-aling energy; (a variabl impedance. con- ,DQQtQd, ircuit with said .ieinductance -.and langularl shiftable,bysaidmotor.devicmes-aid impedance operating to control theimovemerrt ofea potentiah node; along-saidsinductance acicondingfoithe frequency-entire;neomings g- Ina ling-.energyior pro duc ng an'cpt c al reflect representing, (the character ;.of ithe reeeived ie in e rsyw v r10; .rA; televisionesystemzinci idirrgeaireceiv ing; 1 circuit responsrve lto sat predetermined band-r. ofmfirequenc-ies, flan limage" zneproducing screen iin the fonm c'f anzin ductanee connected with said circuit, tan oscillatingzcircuitk con rnected to said-e inductive zscreenzforgprodueing a pre determinedwlow (discharge E the r e011,, an adjustable element-i in asaid losicillating circuit,

v.maearrs controlled; by changesdnifrequencyzof .the incoming; signaling ;-energy yfor go -variably controlling theadjnstment:ofesaidelementffor correspondingly inrodulating it-he glow dischangeionsaidwscreen'rand controlling the movement of potential node along said inductive screen, and connections between said oscillating circuit and said receiving circuit for controlling the intensity of energy supplied to said inductive screen according to the amplitude of the received signaling energy for optically reproducing the character of the received signaling energy.

11. A television receiving system, comprising a receiving circuit responsive to variable frequency television signaling energy,

an output system connected with said receiving circuit including an impedance element and an angularly movable inductance.

device, a stationary inductance device disposed in coacting magnetic relation to said angularly movable inductance device and energized by a constant frequency source of oscillations, an image reproducing screen consisting of a glow discharge inductance,

an oscillating circuit connected with said glow" discharge "inductanceffor' subjecting said glow discharge inductanceto a 'predetermined optical effect; connections from said impedanceelement to said oscillating circuit,

a variabletuning element interposed in circuit between said Oscillating circuit and said glow discharge inductance, a mechanical connection between said angularly movable inductance' deVice'and said variable tuning element for changing the frequency response characteristic of said glow discharge inductance'in relationto the change in frequency.

of the incoming signaling [energy'and modifying the optical eflect'reproduced by said screen. Y

12. A'television receiving system; comprising a receiving circuit responsive to variable 7 coming signaling energy and modifying the frequency television signaling energy an output system connected with said receiving circuit including a resistance member and an angularly movable inductance device, a'stationary inductance device disposed'in coacting magnetic-relation to said angularly movable inductance device and energized'by a constant frequency source of oscillations, an

image reproducing'screen' consisting of a glow discharge inductance, an oscillating circuit connected with said glow discharge inductancefor subjecting said glow discharge inductance 'to'a predetermined optical Tef- ,fect, connections from said resistance memher to said oscillating circuit, a variabletuning element-interposed in circuit between said'o'scillating circuit and said glow discharge inductance, a mechanical connection between said angularly movable inductance 'deviceand'said variable tuning element for changing the frequency response characteristic of'said glow discharge inductance in relation to the change in frequency of the 'inoptical efl'ect reproduced by said screen.

In testimony whereof I aflix my signature. CHESTERL. DAVIS. 

